Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

The domestic and foreign components of pre-tax loss were as follows:

The components of our income tax (benefit) expense were as follows:

	Year Ended December 31,
	2019			2018			2017
	(in thousands)
Current:
Federal	$	—		$	—		$	—
State		113			106			(1,784	)
Foreign		771			2,824			932
Total current income tax (benefit) expense		884			2,930			(852	)
Deferred:
Federal		(277	)		(15	)		(12,287	)
State		(85	)		(40	)		303
Foreign		(129	)		(328	)		(5,506	)
Total deferred income tax (benefit) expense		(491	)		(383	)		(17,490	)
Income tax (benefit) expense	$	393		$	2,547		$	(18,342	)

The following is a reconciliation of the statutory federal income tax rate to our effective tax rate:

	Year Ended December 31,
	2019			2018			2017
Tax benefit (expense) computed at the federal statutory rate		21.0	%		21.0	%		34.0	%
State tax benefit (expense), net of federal benefit		7.6			5.1			3.0
Change in valuation allowance		(38.5	)		(28.4	)		(25.4	)
U.S. corporate tax rate reduction		—			0.2			(11.4	)
Differences between U.S. and foreign tax rates on foreign income		(1.0	)		(0.9	)		(2.4	)
Stock-based compensation benefit (expense)		0.8			(1.2	)		1.1
U.S. federal research & development credit benefit		6.3			5.2			1.4
Acquisitions and divestitures		3.4			0.2			—
Other benefits (expenses)		0.4			(1.4	)		0.2
Total income tax benefit (expense)		0.0	%		(0.2	)%		0.5	%

The significant components of net deferred tax balances were as follows:

	Year Ended December 31,
	2019			2018
	(in thousands)
Deferred tax assets:
Accrued expenses	$	31,746		$	21,056
Intangible assets		172,228			140,494
Stock-based compensation		134,489			254,255
Loss carryforwards		1,201,569			849,224
Tax credit carryforwards		337,497			235,300
Property and equipment		—			203
Lease liability		84,154			—
Other		2,485			1,298
Total deferred tax assets	$	1,964,168		$	1,501,830
Deferred tax liabilities:
Property and equipment	$	(1,420	)	$	—
Convertible debt		(87,904	)		—
Right-of-use asset		(63,595	)		—
Total deferred tax liabilities	$	(152,919	)	$	—
Total net deferred tax assets before valuation allowance		1,811,249			1,501,830
Valuation allowance		(1,811,666	)		(1,502,346	)
Net deferred taxes	$	(417	)	$	(516	)

The following table summarizes the activity related to our gross unrecognized tax benefits during the years ended December 31, 2019 and 2018:

	Year Ended December 31,
	2019			2018
	(in thousands)
Beginning balance of unrecognized tax benefits	$	251,808		$	203,177
Additions for current year tax positions		40,221			43,197
Additions for prior year tax positions		1,977			7,615
Reductions for prior year tax positions		(7,425	)		(1,965	)
Changes due to foreign currency translation adjustments		24			(216	)
Ending balance of unrecognized tax benefits (excluding interest and penalties)	$	286,605		$	251,808
Interest and penalties associated with unrecognized tax benefits		200			260
Ending balance of unrecognized tax benefits (including interest and penalties)	$	286,805		$	252,068